Adelaide United midfielder Adam Griffiths has told his twin brother Joel to remain calm about his Australian national team non-selection. Adam, who has signed a short-term deal with the Reds, believes Joel, who is in China with Beijing Guoan, needs to focus on his performances at club level without getting carried away by the fact that Pim Verbeek once again overlooked for the Socceroos squad.

Joel recently expressed his frustration at not being picked for the squad to take on Indonesia in the final Asian Cup qualifier but Adam said he should simply keep his head down and his opportunity would calm.

"I'd just said to Joel, 'just keep your discipline and keep playing well like you have been,' (and) no one can say anything to him," Adam said.

"I think that's his direction he's going to take."

Joel was the star last week as Beijing defeated reigning A-League champions Melbourne Victory in the opening Asian Champions League group stage match and Adam said more performances like that one would get people talking again.

"I spoke to Joel. He's obviously happy with his performance (against Melbourne)," Adam added.

"He obviously spoke a lot about his exclusion from the Socceroos and he wanted to prove that's he's still got what it takes to be selected."